Cameras used for HtoA are regular Houdini cameras with Arnold properties attached. Arnold properties can be added by selecting the camera and clicking "Add Arnold Properties" in the toolbar or Tab > Arnold > Add Arnold Properties in the network editor. The properties added are regular Houdini spare parameters and any that are Arnold specific are prefixed with ar_.
The types of camera available in Arnold are:
Most of the Houdini parameters are supported except for the ones listed below. Some of the Arnold Properties are only activated depending on Houdini Properties in the View tab. See the specific camera pages for more information.
Background Image, Windows Mask and Crop Mask are not currently supported.
Focus Distance is channel referenced to Focus Distance in the Depth Of Field tab in the Arnold Camera properties.
Bokeh controls are not used.
More information on the Arnold tab can be found in Arnold Camera properties or the separate camera pages.